The MR1 family of Media / Substrate Reactors feature a massive 4-inch reaction chamber. The extra wide design maximizes water to media contact, increasing efficiency and minimizing dead zones in the reactor.

NextReef Reactors have the largest capacities around, giving you the ability to run large amounts of media, or multiple products simultaneously. They're ozone-safe, and perfect for phosphate control, de-nitrification or fluidized sand filtration.

Need more room? Try the MR1 XL - it's 50% larger than the standard MR1 and perfect for larger systems.

MR1 Complete - The MR1 Reactor is now also available complete and ready-to-run with an adjustable flow pump and 4 feet of matching blue tubing. Everything you'll need is in the box - just add your favorite media!

Every NextReef Reactor is hand-crafted in the USA from the highest quality materials, and CAD engineered / CNC cut for a precise fit.

Reactor Use

MR1 Reactors are multi-functional - some suggested uses include:

Phosphate Control Media

Nitrate Control Media

Activated Carbon

Fluidized Sand / Substrate for Bio-Filtration

Sulphur De-Nitrification (Experimental)

Desiccant Air-Drying for Ozone Systems

Calcium Reactor Effluent Treatment / 2nd Stage

MR1 Hang-On Adapter

The MR1 and MR1 Shorty are easily adapted to hang-on applications with the simple, removable MR1 Hang-On Adapter.

What makes NextReef different?

It starts with a superior design and computer-aided engineering. Every joint is channel-cut for maximum strength and bonding area - the tube doesn't just sit on the base and lid, it locks securely into them before bonding. Heavy gauge domestic acrylic , built to withstand even demanding commercial use - no flimsy injection-molded parts to break. Durable, laser-cut filter sponges. The strongest seal on any reactor - 6 thumb screws keep your water in the reactor, not on your floor!

The Best Sealing Lid - Period. The NextReef MR1 features a thumbscrew / keyhole lid - the easiest and most secure way to seal a pressure vessel. Sure, twist lock lids sound great... until you've used one. They're hard to get on, hard to take off, and temperamental at best when it comes to a seal. The lid on the NextReef MR1 comes off easily , and only when you want it to - simply loosen the thumb screws a half-turn, rotate the lid a few degrees and lift off. Commercial grade skimmers and high pressure plumbing systems use a multi-point fastening system, and so does the MR1. It takes longer to machine and finish, but provides a superior result - Uncompromising Quality.